الفهرس 
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Abstract
The present work deals with uranium extraction from sulfate leach liquor of an Egyptian ore material~ namely Gattar (V) (35km west of Hurgbada city) using an extraction technique known as fluidized bed ion - exchange resin. This ore material is characterized by its content of about O. I 2% uranium, a high iron content of 7. I 8% and a relatively high amount of lime (1.61%) beside some deleterious elements in significant amounts e.g. Ti, P, Mo, Th, and Zr. The ore ground to - 60 mesh, was first subjected to sulfuric acid leaching at a fixed pH of 1 which complies with a maximum uranium leaching with minimum gangue dissolution, especially iron (22.2%). This was foHowed by filtration then washing with normal water. Accordingly, this method was used for the preparation of the stock pregnant feed solution which is used for uranium extraction by anion exchange resins. Two different types of resins which are strongly basic anion exchangers were used, name1y~ Amberlite IRA 425 and Amberlite 900 RF. Different sets of equilibrium loading experiments were conducted on a bench scale for the extraction of uranium from the pregnant leach liquor by using the two types of resins. then some equilibrium elution experiments were carried out The loading experiments of anion exchange resins included the effect of the pH on the extraction efficiency of ion exchange resin for the extraction of uranium. the effect of equilibrium contact time. the effect of the initial uranium concentration of the leach liquor on the equilibrium capacity of the resins. the effect of the solution I Resin ratio on the saturation capacity of the resins, the effect of the number of contacts. then the determination of the theoretical number of stages required for uranium extraction.
The pH of 1.75 is more effective on the extraction efficiency of uranium for the two types of resins. However. in the pilot work. 1.65 was used to avoid possible hydrolysis effect The equilibrium contact times are 40 and 50 min .• for Amberlite 1RA425 and 900RF respectively. On the other hand. the saturation capacity of the two types of resin increased by increasing each of the feed concentration of uranium. the pregnant solution 10 resin ratio and the number of contacts of both pregnant solution and resin. However the theoretical number of stages required for uranium extraction was found to be 5 stages for an initial uranium concentration of about 550 ppm for the two types of resins in spite of their different saturation capacities. While at the concentration
of about 900 ppm, the theoretical number of stages was 6 and 5 stages for AmberJite IRA 425 and 900 RF respectively.
The elution experiments were conducted for studying the elution characteristics of the different loaded anion exchange resins. These involved the effect of the contact time and determining the equilibrium isotherms of the elution process. The elution results of anion exchange resins reveal that Amberlite .IRA 425 requires 40 min to reach equilibrium while Amberlite 900 RF requires only 30 miD. However, AmberJite .lRA425 requires five contacts to elute the resin to the level below 6 g II.(w.s.r), while Amberlite 900RF requires only fOUT contacts.
These results were then applied upon a sieve - plate column measuring of 5cm diameter and 60cm height using the two types of resins in a counter current operation with a pregnant feed solution of about 550 ppm concentration at pH 1.65 and which was fed at different flow rates to verity the theoretical number of stages the results of sieve - plate column in case of Amberlite .IRA 425 revealed that the number of stages required for a complete cycle of extraction was six stages which is more by one stage with respect to that estimated trom the theoretical. The operation of the column at these conditions realizes a SIR ratio of ”57” which is less by ”3” tTom that used in the bench scale equilibrium studies. On the other hand, the contact time was ) 6 min representing 37.45% trom that of the equilibrium contact time.
On the other hand in case of the Amberlite 900 RF, the number of stages required for a complete cycle of extraction was six stages, which is more by one stage with respect to that estimated trom the theoretical. The operation of the column at these conditions realizes a SIR ratio of ”69” and a contact time of 22 miD. which represents 42.3% trom that of the equilibrium contact time.